A new double-recessed 4H-SiC MESFET with superior RF characteristics

In this article, a novel double-recessed 4H-SiC MESFET with metal plate (MP) termination technique and recessed source-drain drift region (DRMPR-MESFET) is introduced and its electrical performances are studied by two-dimensional numerical simulation. The MP modifies the electric field in the channel and modulates the surface electric field distribution that leads the further enhancement of the breakdown voltage (V BR). The recessed drift region lowers capacitances. Also it decreases total charge of the channel, lowers the electric field crowding and improves the V BR. In order to combine the advantages of the methods for achieving a high frequency and high V BR device, both of the techniques are taken into consideration together. The simulated results show that the V BR of the DRMPR-MESFET is 139?V in comparison with 120?V of the conventional double-recessed 4H-SiC MESFET with MP termination technique (CDRMP-MESFET), which does not have the recessed source-drain drift region. Also maximum oscillation frequency of the proposed structure improves significantly 267.7%. Furthermore, the maximum available gain of the DRMPR-MESFET is 13.5?dB higher than that of the CDRMP-MESFET, at 50?GHz. Therefore, the DRMPR-MESFET has superior RF performances and higher V BR, and it can be taken into consideration in high frequency and large V BR electrical performances.